Automatic air-pressure equalizer



Dec. 6, 1927.

C. D. JARVIS AUTOMATIC AIR PRESSURE EQUALIZER Filed June 24 1926INVENTOR C.D.Jarvis BY .LBAAIL ATTO R N EY Patented Dec. 6 1927.

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TDMAEI'IG AiIR-P EFSSURE a licat on :file-d June 24, 1926. Serial no,118,202.

This invention relates; to improvements ,in air pressure equalizingdevices l-orthe compressed air supply of Diesel engines,' my principalobject bejingto provide :an automatically operating means. forpreventing the airpressurein the compressor tank rising above apredetermined-pressure.

Engines of this character utilizecompressed air for various purposes,such as starting fuel feeding and scavenging, as well as ,iEor operatingthe whistle if the-installat-ion is on a boat, and are provided with aircompressors operated by the engines themselves.

"The pressure in .thetank is therefore being continuously built up aslong as the engine is in operation, and very frequently such pressure isnot used up as fast as it accumulates. Some means must therefore I withan intake valve automatically opening with the suction stroke of thecompressor piston and automatically closing during the pressure strokeof the piston, and my attachmentprovidos means operated by the airpressure itself tor holding this va-lve constantly open when the airpressure inthe tank exceeds a predetermined amount. This of courseneutralizes the con'rpressive -action ot'the piston and no air will-bedeliver-fed to the tank until the valve is again allowed to functionin'the normal manner.

A further object of my invention is to provide a device for the purposewhich may be readily installed in connection with an air compressorhaving the above type of valve without necessitating any change oralteration in such valve or compressor being made.

. A further object of the invention is to produce a simple andinexpensive device and yet one which will be exceedingly effective torthe purpose for which it is designed.

These objects I accomplish by means of such structure and relativearrangement {of parts as will fully :2 1;ppear.yby a perusal'o'f the doll'o i-ng specification and claims...

In drawings similar characters .of rei'+ erence indicate correspondingpartsin the several views:

Fig 1 is a sectional elevation iolfi myrimproved valve controllingattachment hown as "installed-in connection with a compressor head- 7-.-Fig. 7 2 is a diagrammatic view showing the compressor, Lair tank,and valve controlifeatune's as connected up. Referring nowanoregpartic-ularly to the characters vof reference on the vdatwings thenumeral 1 denotes the air compressoryofthe engine having a reciprocatingpiston 2 therein which is operatedby a connecting rod 8 drivencontinually with :-:th-e operation oi the enginein the usual manner. Inthe head 4 oi the compressor is a downwardly opening intake valve .5 ofthe poppet type having a stem 6 projectingupwardly through the head. Ehevalve is normally held seated by aspring 7. i A pressure pipe 8 leadsfrom .the compressor 1 to areservoir or tank 9 jso that withthe;.'operat-ion of the engine and compressor air will be constantly,

delivered underpressure to the tank. The valve 5 is opened during thesuction stroke of the'pi-ston {and automatically closed :on the-pressurestroke of the piston, but i'fthe va'l-veis constantly held. open itwillbe :evident-that suchpressure stroke will not cause any air to bedelivered to the pipe .8 and the tank. a 1 w 1 -My air pressureequalizing device -ior. ;au tomatically holding the valve openiwhen-thepressure in the tank exceeds a predetermined-amount com-prises a barrel10 dis posed. in vertical alinernent, with the stem tlQThe harrelis heldrigidly in positiontby a bracket member 11 clamped thereto and securedto the compressor head 4. A stem 12 alined with the valve stem 6 isslidable through a combined adjusting nut and bearing member 13'mountedin the bottom of the barrel. The end of the sleeve 12 adjacent the valvestem has a head in the form of an adjustable nut l l so that the normaldistance of said nut from the stem 6 may be regulated to suit. I

The upper end of the stem 12 inside the barrel has a fixed head 15, acompression spring 16 being disposed about said stem between the nut 18and head 15 and tending to force said stem upwardly.

Removably screwed into the top of the barrel is a cylinder 17 into theupper end of which is secured one end of an air pipe 18 leading thenceto the tank 9. A union 19 i is interposed in this pipe intermediate its12 and the piston 21 upwardly, and such movement is of course limited bythe engagement of the member 22 with the rings 24, which also causes therings to be squeezed against the pistonnto aid in maintaining anair-tight seal.

After the structure is assembled in position the head 14 isadjusted sothat it clears thev valve stem sufliciently to allow proper seating ofthe valve. The pressure of the spring 16 is also adjusted by turning theum;

' valve to seat.

13 so that the spring pressure holding the stem 12 away from the valvestem will be equal with the pressure desired to be maintained in thetank 9 before the compressor valve becomes held open. Even though theair pressure is constantly in the pipe 18 and bears against the top ofthe piston, no downward movement of said piston will therefore be haduntil the air pressure overcomes that of the spring. The valve will thenbe opened and held open until the air pressure in the tank is reduced,with the using of the air, toa point where suchair-pressure is less thanthat of the spring. The latter then actsto raise the stem 12 and thepiston, so

as to withdraw the stem 12 from engagement with the valve stem andpermitting the The compressor will then function to again deliver air tothe tank.

By providing a union in the pipe 18 and mounting the cylinder detachablyon the barrel, said cylinder and piston therein may be easily removed asa unit without disturbing the barrel and other parts, so as to enablethe packing structure to be adjusted or replaced when necessary.

From the foregoing description it will bereadily seen that I haveproduced such a de Vice as substantially fulfills the objects of theinvention as set forth herein. 7

WVhile this specification sets forth in detail the present andpref-erred construction of the device, still in practice such deviationsfrom such detail may be resorted to as do not form a departure from thespirit ofthe invention, as defined by the appended claims.

Having thus described my invention what 1 claim as new and useful anddesire to secure by Letters Patent is:

1. An automatic air-pressure equalizer including a stem adapted toengage and open the intake valve of an air-compressor, a plungerseparate from and alined with the stem to engage one end of the same, anen largement on the plunger, a cylinder in which said plunger isslidable, packing rings about the plunger ust beyond the end of theenlargement opposite to the stem, and a spring acting on the stem toforce the same into engagement with the plunger, whereby the enlargementwill then tend to compress the rings and force the same into constantair-tight engagement with the plunger.

2. An automatic airpressureequalizerin cluding a stem adapted to engageand open the intake valve of an air compressor, a plunger separate from.and alined with the stem to engage one end of the same, a barrel inwhich the stem is slidable and a cylinder in which the plunger ismounted detachably on the barrel.

3. Anautomatic air pressure equalizer comprising a stem arranged toengage and,

open a valve; means normally holding the stem from such engagement, abarrel in which the stem and said means are mounted, the barrel beyondthe outer end of the stem being arranged for connection to afluidpressure pipe, and means for-supporting the barrel to maintain thestem therein in definite alinement with the valve.

In testimony whereof I afiix my signature.

CHARLES '1). JARVIS.

CERTIFICATE 0i GURREC'EEQN.

Patent Ne. 1,651,773. Gianted December 6, 1927, m

CHARLES D, JARVES.

it is hereby certified that error appears in em printed speeiiieaiien oithe abeve numbered patent requiring eerreeeien as 'feiiewe: Page 2, line93, claim 2, beiere the word "on" insert the Word "minim-ed"; and thatthe said Letters Patent shouid be read with this eerreeiien eiiereindeaf: the same may conform to the reeerd of the case in the Patent@fiiee.

Signed and seaied this 17th day of January, A D. P928.

M. i. Meere,

Seei. Acting Commissiener of Patents.

